2 câu trả lời
Đáp án+Giải thích các bước giải:
$ (ab-b)+(3a-3)=5\\b(a-1)+3(a-1)=5\\(a-1)(b+3)=5$`=>a-1,b+3\in Ư(5)={+-1;+-5}`
Ta có bảng:
\begin{array}{|c|c|c|}\hline\text{a-1}& \text{1}&\text{-1}&\text{5}&\text{-5}\\\hline \text{b+3}&\text{5}&\text{-5}&\text{1}&\text{-1}\\\hline\text{a}& \text{2}&\text{0}&\text{6}&\text{-4}\\\hline \text{b}&\text{2}&\text{-8}&\text{-2}&\text{-4}\\\hline\end{array}
Vậy `(a,b) \in {(2,2);(0,-8);(6,-2);(-4,-4)}`
